1. Field of the Invention
The invention relates to an undersheet comprising a bottom layer having a plurality of bubble-like supports and a top layer made from a non-woven fabric for use in preventing bed sores in bedridden patients.
2. Description of the Prior Art
The problem of bed sores (decubitus ulcers) is a medical dilemma that has plagued mankind for centuries. The problem arises in bedridden patients when the small capillaries in the skin are under constant pressure. This is common for patients with bone fractures or diseases which take a long time to treat. Continual compression of the capillaries causes them to close down and the flow of blood ceases. The dead cells created in the process break through the surface of the skin forming sores. Sores up to and exceeding 21/2" in diameter have been recorded. Decubitus ulcers generally can not be seen in the developmental stage. Therefore, detection is only possible in later stages--after it is too late to prevent. As a rule of thumb bed sores take approximately two weeks to form and may take as many as two years to get rid of. The bed sore problem is of special concern in today's economy for two major reasons. First, the population is getting older and health care is getting better. Therefore, more people are spending more time in hospital beds. Second, there is an accute shortage of nursing care in proportion to the need. That means there are fewer hospital personnel to turn and massage patients on a regular basis. The combined effect is that there are fewer people to tend more bed ridden people. Therefore, there is a clear need for a means to prevent bed sores which doesn't require additional manpower. Attempts have been made in the past to prevent bed sores.
For example, U.S. Pat. Nos. 3,574,873 and 3,974,532 both describe rubberized mattress products designed to minimize decubitis. In particular, the apparatus described in U.S. Pat. No. 3,974,532 is directed towards a mechanism for promoting ventilation to prevent problems such as "prickly heat".
There are a number of prior art patents directed towards products which include air tight bubbles or blisters. U.S. Pat. Nos. 3,392,081 and 3,661,155 owned by the Sealed Air Corporation are directed towards air filled bubble sheets that don't leak air.
There are also certain prior art devices that employ materials having a plurality of bubbles or blisters in a medical context. The structure described in U.S. Pat. No. 3,812,001 calls for a substrate including a plurality of "air-filled blisters" covered by a top surface. The top surface can be "comprised of a soft woven or a non-woven fabric-like tissue". It is important to note that the structure in U.S. Pat. No. 3,812,001 discloses an "absorbent layer" between the upper layer and the bottom layer. It is believed that the structure shown in U.S. Pat. No. 3,812,001 would not be helpful in minimizing decubitis because the "absorbent layer" would substantially interfere with the flow of fresh air through the material. In addition, it would tend to further distribute the weight of the patient over the entire surface rather than at discrete points.
U.S. Pat. No. 3,468,311 describes another pad which includes perforations for liquids to pass through a layer of air cells to an absorbent layer below. However, the structure disclosed in that patent is not believed to be as effective as the present structure in preventing decubitis ulcers. First, there is no top layer to keep the cell tops from spreading out. Second, by retaining moisture in an absorbent lower pad there is a greater tendency toward skin irritation. Third, there isn't as great as air circulation. Fourth, it is noted that the top area of the air cells in U.S. Pat. No. 3,468,311 is very large therefore making a lot of contact with the skin of the patient. This is exactly the opposite of the purpose and structure of the present invention which is to provide minimal skin support contact. Fifth, and last, a primary purpose of the "Absorbent Pad" of U.S. Pat. No. 3,468,311 appears to be to act as a cushion for the patient. That is not the primary purpose of the undersheet of the present invention which is used to prevent the formation of decubitis ulcers.
U.S. Pat. No. 3,756,884 is of general interest in that is discloses a bubble-type substrate covered by a top film which can be adhered to an intermediate film producing a composite structure. Other than that, the foregoing reference does not appear to be relevant to the present invention. Likewise U.S. Pat. No. 4,099,269 shows a medical device which comprises layers of bubble material. Similarly, U.S. Pat. No. 4,270,659 discloses another medical device employing blister-like materials having certain breathable characteristics.
While the prior art discloses some individual features of interest, none of it, taken singularly or in combination anticipates applicant's novel structure for preventing the miseries of decubitis.